DEVELOPMENT OF BIOLOGICALLY ACTIVE PDGE ANALOGUE IN EUCARYOTIC CELL

摘要

Methods for expressing a variety of biologically active PDGF analogs in eucaryotic cells are disclosed. The methods generally comprise introducing into a eucaryotic host cell a DNA construct capable of directing the expression and secretion of biologically active PDGF analogs in eucaryotic cells. The DNA construct contains a transcriptional promotor followed downstream by a suitable DNA sequence. The DNA sequence may encode a protein substantially homologous or identical to the A-chain or the B-chain of PDGF, or a portion thereof, or an A-B heterodimer. In addition, a portion of the DNA sequence may encode at least a portion of the A-chain, while another portion encodes at least a portion of the B-chain of PDGF. Eucaryotic cells transformed with these DNA constructs are also disclosed. Methods of promoting the growth of mammalian cells, comprising incubating the cells with a biologically active PDGF analog expressed by a eucaryotic host cell transformed with such a DNA construct, are also disclosed. Dimeric proteins having substantially the same biological activity as PDGF are also disclosed. More specifically, the proteins may have two polypeptide chains, one of the chains being a mosaic of amino acid sequences substantially identical to portions of the A- or B-chains of PDGF, the second of the chains being substantially homologous to either the A-chain or the B-chain of PDGF, or each of the chains may be substantially identical to the A-chain of PDGF. Alternatively, each of the two polypeptide chains may be a mosaic of amino acid sequences as described above. In addition, proteins comprising polypeptides that are variants or derivatives of the A- or B-chains of PDGF are also disclosed. Therapeutic compositions containing these proteins and methods for enhancing the wound-healing process in warm-blooded animals are also disclosed.